The invention is directed to a coating for quartz grains or granules used as a filler material for a two-component system hardenable material. The quartz grains are coated with benzoyl peroxide and then with a protective layer covering the coating.
Two-component systems for hardenable material are composed of a resin component and a hardener component, with the components being kept separately and mixed together only when the material is to be used. In a preferred embodiment of the hardenable material, a filler material of quartz grains coated with the hardener component is used.
In a known process, the quartz grains are coated by dissolving granulated polystyrol in toluol and, subsequently, benzoyl peroxide with the quartz grains being added by weight. The toluol is evaporated by subsequent stirring and the blowing-in of air. As a result, the quartz grains are coated in a peroxide layer embedded in polystyrol. This known method is relatively time-consuming, since it requires one to two hours, depending upon the size of the mixer. A further disadvantage is that the toluol released during the coating process must be drawn off and subsequently burned.